Oxygen scavenger and use thereof

ABSTRACT

An oxygen scavenger composition characterized by (1) a catalyst comprising an anthraquinone disulfonic acid or salt thereof and a vanadate salt such as sodium vanadate and (2) a reducing agent such as H2S or hydrazine; and processes for scavenging, with said composition, oxygen from corrosive media including oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media.

1' E1 fies 1e; [191 [11] 3,764,548

[ Oct. 9, 1973 [54] OXYGEN SCAVENGER AND USE THEREOF 3,106,525 10/1963 Schmid et al. 252/8.55 X 3,273,955 9/1966 Goerrig et a1 252/188 X [751 Imam Derek Redmme, Banwm, 3,618,667 11/1971 Snavely 166/275 [73] Assignee: Petrolite Corporation, Wilmington, 3,625,888 12/1971 Redmore et a1. 252/8.55 DeL 3,645,896 2/1972 Larsen 252/8.55

[22] Filed: Sept 1971 Primary Examiner-Herbert B. Guynn [211 App]. No.: 180,091 Attorney-Sidney B. Ring [52] 11.8. C1 252/188, 21/2.7 R, 166/310, [57] ABSTRACT 210/63, 252/8.5 A, 252/8.55 D, 252/8.55 E,

252/178, 252/387, 252/428 252/430 An oxygen scavenger compos1t1on charactenzed by [51] Im Cl (323i 15/00 C23f 11/18 (1) a catalyst comprising an anthraquinone disulfonic [58] Fieid 252/8 D 8 55 E acid or salt thereof and a vanadate salt such as sodium 252/8 188 vanadate and (2) a reducing agent such as H 8 or hyl66/275 6 6 b 7 drazine; and processes for scavenging, with said composition, oxygen from corrosive media including oxy- [56] References Cited gen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness UNITED STATES PATENTS of Said media 1,899,957 3/1933 Gubelmann et a1. 260/370 2,170,596 8/1939 Quiggle 252/188 10 Claims, No Drawings OXYGEN SCAVENGER AND USE THEREOF The presence of air or oxygen increases the corrosiveness of a system, for example, drilling fluids or air drilling systems used in drilling oil and gas wells, brines employed in the secondary recovery of petroleum by water flooding and in the disposal of waste water and brines from oil and gas wells, steam generating systems, water circulating systems, automobile radiators, diesel locomotive engines, boiler water, sea water ship ballast, etc; in fact, in any system where oxygen or air is present, its presence causes or increases corrosion. Therefore it is highly desirable to remove oxygen from such systems. The practice of removing dissolved oxygen from such systems is so well known that the agent employed to achieve this result is known as an oxygen scavenger.

Although oxygen scavengers are effective in certain systems, they often pose difficulties therein. For example, sodium bisulfite employing a cobalt catalyst is not effective as an oxygen scavenger in the presence of H S because the cobalt catalyst is deactivated by H 8. Furthermore, the bisulfite system is not effective as an oxygen scavenger in the presence of polyamine-derived corrosion inhibitors, the most widely used corrosion inhibitors, since they inactivate the oxygen scavenging system.

I have now discovered an oxygen scavenger system which is characterized by (l) a catalyst comprising an anthraquinone disulfonic acid (A) and a vanadate salt such as sodium vanadate (Na VO and (2) a reducing agent such as H 8, hydrazine, etc.

This system is also effective in the presence of H 8 and polyamine-derived corrosion inhibitors. In fact, the presence of H S in the oxygen containing system, which generally produces a particularly corrosive system, is turned to an advantage in the present invention in that H 8 acts as the reducing agent.

The oxygen scavenging reaction may be summarized as follows:

In general, the system is employed in two ways l by adding the AQ/Na VO mixture to the system followed by the addition of the reducing agent or (2) prereducing the AQ/Na VO mixture with the reducing agent prior to addition to the oxygen-containing system. However, where the oxygen-containing system also contains H 5, an extremely corrosive system, it is necessary to add only the AQ/Na VO mixture since H 8 acts as the reducing agent.

All the known isomers of anthraquinone disulphonic acid are suitable for use in this process. These are:

Anthraquinone-l,5-disulphonic acid.

Anthraquinone-l,6-disulphonic acid.

Anthraquinone-l,7-disulphonic acid.

Anthraquinone-1,8-disulphonic acid.

Anthraquinone-2,6-disulphonic acid.

Anthraquinone-Z,7-disulphonic acid.

Also mixtures of these isomers may be used with advantage, including commercially available mixtures which contain 1,5/1,8 or 2,6/2,7 anthraquinone disulphonic acids and possibly small quantities of other isomers. Salts of these sulfonic acids are also included within the scope of the invention, for example, alkali metal salts, alkali earth salts, etc.

Any suitable vanadate salt can be employed such as alkali metal vanadates, most preferably sodium or potassium vanadates.

Any effective ratios of anthraquinones to vanadate can be employed, such as from about 15:1 to 1:15, for example from about 10:1 to 1:10, but preferably from about 5:1 to 1:5.

Any effective concentration of anthraquinone can be employed, depending in part on the concentration of oxygen present, for example at least 10 ppm, such as from about 10 to 500 ppm, for example from about 20 to 250 ppm, but preferably from about 20 to ppm per ppm of oxygen. Greater amounts can be employed where desired, but there is generally no economic advantage in doing so.

The amount of H 8 or hydrazine present in the system should be sufficient to reduce the oxygen.

The following examples are presented by way of illustration and not of limitation.

All examples were carried out using 200 ml of tapwater at approximately 20C contained in a conical flask in which the oxygen probe is inserted. The oxygen concentrations vs. time are recorded on strip chart recorder connected to the oxygen meter. The rates of oxygen removal listed below are obtained by determining reduction of oxygen content in 10 minutes (or in time to reduce to zero if less than 10 minutes). The initial oxygen content varies from 7 to 8 ppm.

Table 1 presents the rate of oxygen removal vs. hydrazine concentration, using a solution containing vanadate and anthraquinone.

TABLE 1 "Van- Rate of *Quinone adate l-lydrazine Oxygen Example (ppm) (ppm) (ppm) Removal (ppm min.") 1 500 250 500 2 500 250 l 4 3 500 250 31 0 62 4 500 250 15 0.57 5 250 125 125 0.74 6 250 125 62.5 0.64 7 250 125 31 0.50 8 250 125 125 0.66 9 250 125 250 1.28 10 250 125 7.5 0.18

* Quinone refers to anthraquinone 2,6-disulfonic acid, sodium salt in Table l-5.

** Vanadate refers to sodium vanadate in Tables l-S.

The following table shows rate of oxygen removal employing a quinone/vanadate ratio of 1:1 with hydrazine or H S as reducer.

TABLE 2 Rate of Oxygen Example Reducing System (ppm) Removal (ppm min. 1 1 Quinone (125) Vanadate (125) Hydrazine (125) 1.55 12 Quinone (125) vanadate (125) Hydrazine (31) 0.45 13 Quinone (62.5) vanadate (62.5)

Hydrazine (125) 0.40 14 Quinone (125) Vanadate (125) H S (10) 0.90 15 Quinone (125) Vanadate (125) The following table, Table 3, shows the importance of both quinone and vanadate using hydrazine as reducing agent.

TABLE 3 Rate of Oxygen Example Quinone Vanadate Hydrazine Removal (pp (pm) (pm) (pp Table 4 illustrates the effect of various ratios of quinone/vanadate. In all cases H 8 is reducing agent at approximately 20-30 ppm.

TABLE 4 Vana- Quinone date Rate of Oxygen Removal Example (PPm) (ppm) (ppm min) 23 250 0 0.08 24 125 125 2.56 25 I00 125 2.4 26 50 125 1.18 27 25 125 0.60 28 10 125 0.50 29 10 125 0.42 30 I25 100 2.0 31 I25 50 1.8 32 125 25 0.88 33 125 10 0.16

Table 5 illustrates effect of added corrosion inhibitor (H 5 is employed as reducing agent).

TABLE 5 Vana- Rate of Quinone date Inhibitor Oxygen Removal Example (ppm) (ppm) (ppm) (ppm min) 34 125 125 None 2.8 35 125 125 *A (1000) 1.65 36 125 125 "B (1000) 1.24

* Inhibitor A is the reaction product of a polyamine and a fatty acid.

** Inhibitor B is polymeric imidzaoline as described in US. Pat. No. 3,450,646.

I. a compound selected from the group consisting of anthraquinone 1,5-disulfonic acid, anthraquinone 1,6-disulfonic acid, anthraquinone 1,7-disulfonic acid, anthraquinone 1,8 disulfonic acid, anthraquinone 2,6-disulfonic acid, anthraquinone 2,7-disulfonic acid, mixtures thereof, alkali metal salts thereof, alkali earth salts thereof, and mixtures thereof, and

2. alkali metal vanadate salt,

and

II. reducing agent selected from the group consisting of H 8, hydrazine and mixtures thereof, 11 being present in an amount sufficient to reduce the oxygen present,

I being present in an amount sufficient to catalyze the reaction between the oxygen present and II, the ratio of the amount OH (1) to I (2) being from about 15:1 to 1:15.

2. The composition of claim 1 where 11 is H 8 or hydrazine.

3. The composition of claim 2 where 11 (2) is sodium vanadate.

4. The composition of claim 3 where II is H 8.

5. The composition of claim 3 where 11 is hydrazine.

6. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim 1.

7. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim 2.

8. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim 3.

9. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim 4.

10. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim 5. 

2. alkali metal vanadate salt, and II. reducing agent selected from the group consisting of H2S, hydrazine and mixtures thereof, II being present in an amount sufficient to reduce the oxygen present, I being present in an amount sufficient to catalyze the reaction between the oxygen present and II, the ratio of the amount of I (1) to I (2) being from about 15:1 to 1:15.
 2. The composition of claim 1 where II is H2S or hydrazine.
 3. The composition of claim 2 where II (2) is sodium vanadate.
 4. The composition of claim 3 where II is H2S.
 5. The composition of claim 3 where II is hydrazine.
 6. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim
 1. 7. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or To increase the corrosiveness of said media characterized by adding to said media the composition of claim
 2. 8. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim
 3. 9. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim
 4. 10. A process of scavenging oxygen from aqueous corrosive media having oxygen or air wherein said oxygen or air causes said media to be corrosive or to increase the corrosiveness of said media characterized by adding to said media the composition of claim
 5. 